Connoisseur’s Choice: Malachite Pseudomorphs after Azurite—Part 2: Milpillas, Mexico and Other Worldwide Localities

Abstract

Pseudomorphs of malachite after azurite are reasonably common in nature and are highly sought-after by mineral collectors; a tendency for sharp preservation of the original azurite habit coupled with strong, bright colors makes for attractive specimens. In Part 1 of this article, Southwood and Cairncross (2022) featured pseudomorphs of malachite after azurite from two classic localities, Bisbee, Arizona, and the Tsumeb mine in Namibia, and discussed aspects of the replacement mechanism on the scale of individual crystals. The featured locality for Part 2 (with an expanded author base) is the Milpillas mine, Sonora, Mexico, which, as noted previously, sets the modern benchmark for fine specimens of these replacements. Across the U.S. border in Arizona, a number of localities besides Bisbee have